Piston expander



April 13, 1 3- v. D. ACKERMAN PISTON EXPANDER I Filed July 20, l942 INVENTOR.

Patented Apr. 13, 1943 Virgil D. Ackerinan,

Hastings, Mich., assignor to Hastings Manufacturing Company, Hastings, Mich., a corporation of Michigan Original application Feb 430,563. Divided an 1942, Serial No.

6 Claims.

This invention relates to improvements in piswith curved piston wall engaging portions of substantial area engaging the piston wall with a snubbing action thereby preventing undesirable breathing action.

Third, to provide a piston expander which may be handled and installed as a unit by driving into action.

Objects relating to details and economies of the invention will apear from the description to follow. The invention is defined and pointed out inthe claims. 1

A preferred embodiment of the invention is illustrated in the accompanying drawing, in which:

Fig. 1 is an inverted view of a non-split type of internal combustion engine piston with an expander embodying my invention installed therein, the piston and expander being partially sectioned and partially broken away, the section being on line of Fig. 2.

Fig. 2 is a fragmentary side elevation of the structure shown in Fig. 1 partially in longitudinal section on line 22 of Fig. 1.

Fig. 3 is a side elevation of the expander.

Fig. 4 is a perspective view thereof.

In the accompanying drawing, I represents an internal combustion engine piston having a nonsplit skirt 2. 3 represents the piston pin bosses and 4 the piston pin.

The expander of my invention comprises a pair of relatively wide blade spring members 5 having outwardly curved portions 6 at their outer ends, these curved portions being of substantial areathat is, the curves being of substantial arc and also of considerable area longitudinally of the piston, extending throughout a substantial part of the length of the piston skirt 2' as shown in Fig. 2. These curved piston'wall engaging portions 6 merge into abutting portions 1 which are substantially spaced from the cylinder wall contacting portions by permitting a resilient snubbing piston wall engagement. The abutting ruary 12, 1942, Serial No. d this application July 20, 451,599

portions are secured together preferably by the single rivet 8. These abutting portions merge into the inwardly diverging portions 9 by means of the short reverse curves l0.

These portions 9 are sharply divergent and terminate insubstantially parallel inner terminal portionsl I having curved seats l2 at their inner edges engageable with the piston pin bosses 3 which constitute abutment members for the expander. The inner edges of the expander members at the inner sides of the seats I2 have long bevels or inclined portions I3 which facilitate the expander members being driven into a piston as a unit.

The expander members coact to provide an arch with springable sides. There is also substantial resilience in the cylinder wall engaging portions 6. However, these, as stated,,have a snubbing engagement with the cylinder wall which is effective in preventing an undesirable breathing action. When the expander is driven into a piston, the parts are placed under spring stress so that they are eifectively retained with the seats l2 engaging the abutting members in the piston, as in the embodiment illustrated, with the piston pin bosses. The expander cannot become angularly displaced in the piston as the parts are so related that they coact to stabilize and support each other.

I have illustrated and described my improvements in an embodiment which I have found highly practical. I have not attempted to illustrate or described certain modifications or adaptations which might be desirable for particular expanders as it'is believed that this disclosure will enable those skilled in the art to embody or adapt my invention as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. A piston expander comprising a pair of blade spring members having outwardly curved piston wall engaging portions at their outer ends of substantial area for engagement with a piston wall axially thereof, and coacting abutting portions adjacent and merging into said cylinder wall engaging portions, said coacting abutting portions being secured together by a single rivet at a point permitting springable substantial independent snubbing engagement of the said curved outer ends of the expander members with a piston wall, said expander members sharply diverging from said abutting portions and terminating in substantially parallel inner end portions having abutment receiving seats of substantial depth in their inner edges, their inner edges at the inner sides of the seats being inclined to facilitate the expander members being driven into a piston having pin bosses as an 1 assembled unit, to engage said seats with said gaging portions, said coacting. abutting portions being secured together by a single rivet'at a point permitting springable substantial independent snubbing engagement of the said curved outer ends of the expander members with a piston wall, said expanded members sharply diverging from said abutting portions, and terminating in substantially parallel inner end portions having abutment receiving seats in their inner edges.

3, A-piston expander comprising a pair of blade spring members having oppositely curved piston wall engaging portions at their outer ends of substantial area for engagement with a piston wall axially thereof, and coacting abutting portions adjacent and merging into said cylinder wall engaging portions, said coacting abutting portions being secured together at a point permitting substantial independent springable snubbing engagement of the said curved outer ends of the expander members with a piston wall, said expander members having inwardly diverging springable portions merging into said abutting portions with reverse curves, said expander members having abutment receiving seats of substantial depth in their inner edges, their inner edges at the inner sides of the seats being inclined to facilitate the expander members being driven into a piston as an assembled unit, to engage said seats with the piston pin bosses of said piston.

4. A piston expander comprising a pair of blade spring members having oppositely curved piston wall engaging portions at their outer ends of substantial area for engagement with a piston bers having abutment receiving seats in their inner edges.

'5. A piston expander comprising a pair of blade-spring expander members having curved piston wall engaging portions at their outer ends of substantial area for engagement with a piston wall axially thereof, and coacting abutting portions adjacent said curved piston wall engaging portions, said coacting abutting portions being secured together at a point substantially spaced from their curved cylinder wall engaging portions, permitting substantial independent snubbing engagement of the said curved outer ends of the expander members with a piston wall, said expander members having abutment receiving seats of substantial depth in their inner edges, their inner edges at the inner side of the said seats being inclined, to facilitate the expander members being driven into a piston to engage said seats with parts of a piston constituting abutment members.

6. A piston expander comprising a pair of blade-spring expander members having curved piston wall engaging portions at their outer ends of substantial area for engagement with a piston wall axiall thereof, and coacting abutting portions adjacent said curved piston wall engaging portions, said coacting abutting portions being secured together at a point substantially spaced from their said curved cylinder wall engaging portions, permitting substantial independent snubbing engagement of the said curved outer ends of the expander members with a piston wall, said expander members having abutment receiv ing seats in their inner edges.

VIRGIL D. ACKERMAN. 

